has role has role is conjugate base of is conjugate acid of is tautomer of is enantiomer of cysteine L-alpha-amino acid D-cysteine L-cysteine CYSTEINE CHEBI:13095 Cys L-Zystein (R)-2-amino-3-mercaptopropanoic acid An optically active form of cysteine having <small>L</small>-configuration. CHEBI:41811 L-Cystein E920 CHEBI:41781 L-Cysteine CHEBI:17561 CHEBI:41768 (2R)-2-amino-3-sulfanylpropanoic acid chebi_ontology CHEBI:41227 CHEBI:41700 E 920 C CHEBI:6207 E-920 CHEBI:21261 FREE CYSTEINE L-Cysteine CYSTEINE (2R)-2-amino-3-mercaptopropanoic acid L-2-Amino-3-mercaptopropionic acid serine family amino acid L-cysteinate(1-) L-cysteinium L-cysteine zwitterion flour treatment agent EC 4.3.1.3 (histidine ammonia-lyase) inhibitor human metabolite proteinogenic amino acid